Bacteria-seeded plastic is tough and degradable

Unassuming little bacteria make plastic stronger while in use but then break it down at the end of life ( Nat. Commun. 2024, DOI: 10.1038/s41467-024-47132-8 ). Engineers embedded spores of a polymer- munching bacteria into thermoplastic polyurethane (TPU), a rubbery plastic used to make shoe insoles, cushions, and phone cases. When the material is thrown into compost, the bacteria germinate and disintegrate the plastic. Most TPU plastics used today end up in landfills. Some researchers are starting with biobased materials to make degradable or recyclable TPUs, but the materials' mechanical properties are inferior to those of conventional TPU. Nanoengineer Jonathan K. Pokorski and bioengineer Adam M. Feist of the University of California San Diego and their colleagues harnessed bacteria because some strains have been found to employ polyurethanes as a carbon source. After evaluating several strains, the researchers chose Bacillus subtilis , which is a component in probiotics. They used